Effect of commercial diets on growth performance and stress in tomato clownfish (Amphipriom frenatus): A first approach

Abstract

The genus Amphiprion, which species are typically known as clownfish or anemone fish, are among the most commercialized marine ornamental fish species in the world. The present study evaluated three commercial aquaculture diets (A = 40% protein and 9% of crude fat, B = 45% protein and 14% of crude fat, C = 38% protein and 6% of crude fat) on the growth performance and stress response of juveniles of the tomato clownfish A. frenatus during six weeks. Initial and final weight, length, weight gain, relative weight gain, condition factor, specific growth rate and survival were evaluated to determine growth performance. To analyze the stress response, individuals were subjected to a novel environment and a mirror test both performed on the second and fifth week of the experiment. Results demonstrated that diet B significantly increased (P < 0.05) weight and length, weight gain, relative weight gain, specific growth rate and had a better feed conversion rate. In terms of the stress response, fish from treatment B exhibited higher activity and higher swimming velocity (P < 0.05). Additionally, fish from same diet remained closer to the mirror and performed more attacks attempts than fish from treatments A and C. Furthermore, tomato clownfish showed consistent behavioural responses over time. These results demonstrate that diets not only influences growth performance, but also impacts the stress response of juvenile tomato clownfish. This might be of interest to the aquaculture industry of this fish species to select adequate diets and to develop protocols to improve welfare of fish kept in captivity.